According to recent data, almost all adults show clinical signs of inflammation in the gums, gingivitis, at one or more tooth sites. About 11% of the population shows pronounced destruction of the tooth supporting tissues, i.e. periodontitis. The clinical signs of inflammation are redness, bleeding on probing and suppuration. However, these clinical parameters are not reliable predictors of tissue destruction.
Most, if not all forms, of periodontal diseases are caused by bacteria. Recent clinical and microbial investigations have revealed that specific gram negative bacteria play an ethological role in different forms of human periodontal diseases. Porphyromonas gingivalis has been associated with progressive adult periodontitis. Thus, the presence of P. gingivalis could be used as a guideline for selection of treatment regime and for treatment evaluation. Identification of P. gingivalis is commonly performed using cultivation techniques. Microbial sampling and culturing is usually performed as in the following example:
Sterile paperpoints are inserted into the periodontal pocket and left in place for 15 s. The points are pooled in a vial containing glass beads and transport medium. At the microbial laboratory, the samples are thoroughly desintegratcd and diluted. A volume of 0.1 ml from each dilution as well as from the undiluted sample is distributed on the surface of Brucella agar plates (BBL Microbiology Systems, Cockeysville, Md., USA) enriched with 5% defibrinated horse blood, 0.5% haemolyzed blood and 5 mg/l of menadion. After 7-9 days of incubation, in jars with 95% H.sub.2 and 5% CO.sub.2, total viable count and the number of P. gingivalis colonies in the sample is determined. The P. gingivalis colonies are identified by gram staining, lactose fermentation test, and checking for production of red fluorescence in long-wave (360 nm) UV-light. The handling of the sample is time consuming and personal intensive and therefore expensive. Also it will take about 2 weeks before the therapist can have the result of the test.
Today about 3000 microbial samples are sent for analysis to the Dept of Oral Microbiology in Goteborg. This laboratory is one of the 4 Oral Microbiology Departments in Sweden to which samples could be sent for analysis. The cost for the analysis of 1 sample is 150 SEK, which limits the number of samples taken from each patient. P. gingivalis is known to produce high proteolytic activity which can a) destroy in vitro many components of connective tissue and b) degrade other proteins important for the maintaining of local homeostasis e.g. the inactivating of inhibitors controlling host proteinases.
EP-A2 0 255 341 (Sunstar Kabushiki Kaisha) discloses a periodontal diagnosis reagent, which comprises peptide(s) having attached thereto a colour developing group for detecting aminopeptidase-like enzymatic activity in an oral sample. EP-A2 0 292 708 (The Research Foundation of State University of New York) relates to detection of Bacteroides gingivalis using a serum aminopeptidase inhibitor in an assay system, and measuring the ability to hydrolyse N-carbobenzoxy-glycyl-glycyl-L-arginine-.beta.-naphtylamide derivatives. Use of enhancers of the enzymatic activity of Bacteroides gingivalis such as chelating materials, specifically tetrasodium ethylene-diaminetetraacetate (EDTA) is proposed.